xref: /freebsd/contrib/llvm-project/llvm/lib/IR/DebugInfoMetadata.cpp (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 //===- DebugInfoMetadata.cpp - Implement debug info metadata --------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the debug info Metadata classes.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/IR/DebugInfoMetadata.h"
14 #include "LLVMContextImpl.h"
15 #include "MetadataImpl.h"
16 #include "llvm/ADT/SmallSet.h"
17 #include "llvm/ADT/StringSwitch.h"
18 #include "llvm/BinaryFormat/Dwarf.h"
19 #include "llvm/IR/Function.h"
20 #include "llvm/IR/Type.h"
21 #include "llvm/IR/Value.h"
22 
23 #include <numeric>
24 
25 using namespace llvm;
26 
27 namespace llvm {
28 // Use FS-AFDO discriminator.
29 cl::opt<bool> EnableFSDiscriminator(
30     "enable-fs-discriminator", cl::Hidden,
31     cl::desc("Enable adding flow sensitive discriminators"));
32 } // namespace llvm
33 
34 const DIExpression::FragmentInfo DebugVariable::DefaultFragment = {
35     std::numeric_limits<uint64_t>::max(), std::numeric_limits<uint64_t>::min()};
36 
37 DILocation::DILocation(LLVMContext &C, StorageType Storage, unsigned Line,
38                        unsigned Column, ArrayRef<Metadata *> MDs,
39                        bool ImplicitCode)
40     : MDNode(C, DILocationKind, Storage, MDs) {
41   assert((MDs.size() == 1 || MDs.size() == 2) &&
42          "Expected a scope and optional inlined-at");
43 
44   // Set line and column.
45   assert(Column < (1u << 16) && "Expected 16-bit column");
46 
47   SubclassData32 = Line;
48   SubclassData16 = Column;
49 
50   setImplicitCode(ImplicitCode);
51 }
52 
53 static void adjustColumn(unsigned &Column) {
54   // Set to unknown on overflow.  We only have 16 bits to play with here.
55   if (Column >= (1u << 16))
56     Column = 0;
57 }
58 
59 DILocation *DILocation::getImpl(LLVMContext &Context, unsigned Line,
60                                 unsigned Column, Metadata *Scope,
61                                 Metadata *InlinedAt, bool ImplicitCode,
62                                 StorageType Storage, bool ShouldCreate) {
63   // Fixup column.
64   adjustColumn(Column);
65 
66   if (Storage == Uniqued) {
67     if (auto *N = getUniqued(Context.pImpl->DILocations,
68                              DILocationInfo::KeyTy(Line, Column, Scope,
69                                                    InlinedAt, ImplicitCode)))
70       return N;
71     if (!ShouldCreate)
72       return nullptr;
73   } else {
74     assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
75   }
76 
77   SmallVector<Metadata *, 2> Ops;
78   Ops.push_back(Scope);
79   if (InlinedAt)
80     Ops.push_back(InlinedAt);
81   return storeImpl(new (Ops.size(), Storage) DILocation(
82                        Context, Storage, Line, Column, Ops, ImplicitCode),
83                    Storage, Context.pImpl->DILocations);
84 }
85 
86 const DILocation *
87 DILocation::getMergedLocations(ArrayRef<const DILocation *> Locs) {
88   if (Locs.empty())
89     return nullptr;
90   if (Locs.size() == 1)
91     return Locs[0];
92   auto *Merged = Locs[0];
93   for (const DILocation *L : llvm::drop_begin(Locs)) {
94     Merged = getMergedLocation(Merged, L);
95     if (Merged == nullptr)
96       break;
97   }
98   return Merged;
99 }
100 
101 const DILocation *DILocation::getMergedLocation(const DILocation *LocA,
102                                                 const DILocation *LocB) {
103   if (!LocA || !LocB)
104     return nullptr;
105 
106   if (LocA == LocB)
107     return LocA;
108 
109   SmallPtrSet<DILocation *, 5> InlinedLocationsA;
110   for (DILocation *L = LocA->getInlinedAt(); L; L = L->getInlinedAt())
111     InlinedLocationsA.insert(L);
112   SmallSet<std::pair<DIScope *, DILocation *>, 5> Locations;
113   DIScope *S = LocA->getScope();
114   DILocation *L = LocA->getInlinedAt();
115   while (S) {
116     Locations.insert(std::make_pair(S, L));
117     S = S->getScope();
118     if (!S && L) {
119       S = L->getScope();
120       L = L->getInlinedAt();
121     }
122   }
123   const DILocation *Result = LocB;
124   S = LocB->getScope();
125   L = LocB->getInlinedAt();
126   while (S) {
127     if (Locations.count(std::make_pair(S, L)))
128       break;
129     S = S->getScope();
130     if (!S && L) {
131       S = L->getScope();
132       L = L->getInlinedAt();
133     }
134   }
135 
136   // If the two locations are irreconsilable, just pick one. This is misleading,
137   // but on the other hand, it's a "line 0" location.
138   if (!S || !isa<DILocalScope>(S))
139     S = LocA->getScope();
140   return DILocation::get(Result->getContext(), 0, 0, S, L);
141 }
142 
143 Optional<unsigned> DILocation::encodeDiscriminator(unsigned BD, unsigned DF,
144                                                    unsigned CI) {
145   std::array<unsigned, 3> Components = {BD, DF, CI};
146   uint64_t RemainingWork = 0U;
147   // We use RemainingWork to figure out if we have no remaining components to
148   // encode. For example: if BD != 0 but DF == 0 && CI == 0, we don't need to
149   // encode anything for the latter 2.
150   // Since any of the input components is at most 32 bits, their sum will be
151   // less than 34 bits, and thus RemainingWork won't overflow.
152   RemainingWork =
153       std::accumulate(Components.begin(), Components.end(), RemainingWork);
154 
155   int I = 0;
156   unsigned Ret = 0;
157   unsigned NextBitInsertionIndex = 0;
158   while (RemainingWork > 0) {
159     unsigned C = Components[I++];
160     RemainingWork -= C;
161     unsigned EC = encodeComponent(C);
162     Ret |= (EC << NextBitInsertionIndex);
163     NextBitInsertionIndex += encodingBits(C);
164   }
165 
166   // Encoding may be unsuccessful because of overflow. We determine success by
167   // checking equivalence of components before & after encoding. Alternatively,
168   // we could determine Success during encoding, but the current alternative is
169   // simpler.
170   unsigned TBD, TDF, TCI = 0;
171   decodeDiscriminator(Ret, TBD, TDF, TCI);
172   if (TBD == BD && TDF == DF && TCI == CI)
173     return Ret;
174   return None;
175 }
176 
177 void DILocation::decodeDiscriminator(unsigned D, unsigned &BD, unsigned &DF,
178                                      unsigned &CI) {
179   BD = getUnsignedFromPrefixEncoding(D);
180   DF = getUnsignedFromPrefixEncoding(getNextComponentInDiscriminator(D));
181   CI = getUnsignedFromPrefixEncoding(
182       getNextComponentInDiscriminator(getNextComponentInDiscriminator(D)));
183 }
184 dwarf::Tag DINode::getTag() const { return (dwarf::Tag)SubclassData16; }
185 
186 DINode::DIFlags DINode::getFlag(StringRef Flag) {
187   return StringSwitch<DIFlags>(Flag)
188 #define HANDLE_DI_FLAG(ID, NAME) .Case("DIFlag" #NAME, Flag##NAME)
189 #include "llvm/IR/DebugInfoFlags.def"
190       .Default(DINode::FlagZero);
191 }
192 
193 StringRef DINode::getFlagString(DIFlags Flag) {
194   switch (Flag) {
195 #define HANDLE_DI_FLAG(ID, NAME)                                               \
196   case Flag##NAME:                                                             \
197     return "DIFlag" #NAME;
198 #include "llvm/IR/DebugInfoFlags.def"
199   }
200   return "";
201 }
202 
203 DINode::DIFlags DINode::splitFlags(DIFlags Flags,
204                                    SmallVectorImpl<DIFlags> &SplitFlags) {
205   // Flags that are packed together need to be specially handled, so
206   // that, for example, we emit "DIFlagPublic" and not
207   // "DIFlagPrivate | DIFlagProtected".
208   if (DIFlags A = Flags & FlagAccessibility) {
209     if (A == FlagPrivate)
210       SplitFlags.push_back(FlagPrivate);
211     else if (A == FlagProtected)
212       SplitFlags.push_back(FlagProtected);
213     else
214       SplitFlags.push_back(FlagPublic);
215     Flags &= ~A;
216   }
217   if (DIFlags R = Flags & FlagPtrToMemberRep) {
218     if (R == FlagSingleInheritance)
219       SplitFlags.push_back(FlagSingleInheritance);
220     else if (R == FlagMultipleInheritance)
221       SplitFlags.push_back(FlagMultipleInheritance);
222     else
223       SplitFlags.push_back(FlagVirtualInheritance);
224     Flags &= ~R;
225   }
226   if ((Flags & FlagIndirectVirtualBase) == FlagIndirectVirtualBase) {
227     Flags &= ~FlagIndirectVirtualBase;
228     SplitFlags.push_back(FlagIndirectVirtualBase);
229   }
230 
231 #define HANDLE_DI_FLAG(ID, NAME)                                               \
232   if (DIFlags Bit = Flags & Flag##NAME) {                                      \
233     SplitFlags.push_back(Bit);                                                 \
234     Flags &= ~Bit;                                                             \
235   }
236 #include "llvm/IR/DebugInfoFlags.def"
237   return Flags;
238 }
239 
240 DIScope *DIScope::getScope() const {
241   if (auto *T = dyn_cast<DIType>(this))
242     return T->getScope();
243 
244   if (auto *SP = dyn_cast<DISubprogram>(this))
245     return SP->getScope();
246 
247   if (auto *LB = dyn_cast<DILexicalBlockBase>(this))
248     return LB->getScope();
249 
250   if (auto *NS = dyn_cast<DINamespace>(this))
251     return NS->getScope();
252 
253   if (auto *CB = dyn_cast<DICommonBlock>(this))
254     return CB->getScope();
255 
256   if (auto *M = dyn_cast<DIModule>(this))
257     return M->getScope();
258 
259   assert((isa<DIFile>(this) || isa<DICompileUnit>(this)) &&
260          "Unhandled type of scope.");
261   return nullptr;
262 }
263 
264 StringRef DIScope::getName() const {
265   if (auto *T = dyn_cast<DIType>(this))
266     return T->getName();
267   if (auto *SP = dyn_cast<DISubprogram>(this))
268     return SP->getName();
269   if (auto *NS = dyn_cast<DINamespace>(this))
270     return NS->getName();
271   if (auto *CB = dyn_cast<DICommonBlock>(this))
272     return CB->getName();
273   if (auto *M = dyn_cast<DIModule>(this))
274     return M->getName();
275   assert((isa<DILexicalBlockBase>(this) || isa<DIFile>(this) ||
276           isa<DICompileUnit>(this)) &&
277          "Unhandled type of scope.");
278   return "";
279 }
280 
281 #ifndef NDEBUG
282 static bool isCanonical(const MDString *S) {
283   return !S || !S->getString().empty();
284 }
285 #endif
286 
287 dwarf::Tag GenericDINode::getTag() const { return (dwarf::Tag)SubclassData16; }
288 GenericDINode *GenericDINode::getImpl(LLVMContext &Context, unsigned Tag,
289                                       MDString *Header,
290                                       ArrayRef<Metadata *> DwarfOps,
291                                       StorageType Storage, bool ShouldCreate) {
292   unsigned Hash = 0;
293   if (Storage == Uniqued) {
294     GenericDINodeInfo::KeyTy Key(Tag, Header, DwarfOps);
295     if (auto *N = getUniqued(Context.pImpl->GenericDINodes, Key))
296       return N;
297     if (!ShouldCreate)
298       return nullptr;
299     Hash = Key.getHash();
300   } else {
301     assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
302   }
303 
304   // Use a nullptr for empty headers.
305   assert(isCanonical(Header) && "Expected canonical MDString");
306   Metadata *PreOps[] = {Header};
307   return storeImpl(new (DwarfOps.size() + 1, Storage) GenericDINode(
308                        Context, Storage, Hash, Tag, PreOps, DwarfOps),
309                    Storage, Context.pImpl->GenericDINodes);
310 }
311 
312 void GenericDINode::recalculateHash() {
313   setHash(GenericDINodeInfo::KeyTy::calculateHash(this));
314 }
315 
316 #define UNWRAP_ARGS_IMPL(...) __VA_ARGS__
317 #define UNWRAP_ARGS(ARGS) UNWRAP_ARGS_IMPL ARGS
318 #define DEFINE_GETIMPL_LOOKUP(CLASS, ARGS)                                     \
319   do {                                                                         \
320     if (Storage == Uniqued) {                                                  \
321       if (auto *N = getUniqued(Context.pImpl->CLASS##s,                        \
322                                CLASS##Info::KeyTy(UNWRAP_ARGS(ARGS))))         \
323         return N;                                                              \
324       if (!ShouldCreate)                                                       \
325         return nullptr;                                                        \
326     } else {                                                                   \
327       assert(ShouldCreate &&                                                   \
328              "Expected non-uniqued nodes to always be created");               \
329     }                                                                          \
330   } while (false)
331 #define DEFINE_GETIMPL_STORE(CLASS, ARGS, OPS)                                 \
332   return storeImpl(new (array_lengthof(OPS), Storage)                          \
333                        CLASS(Context, Storage, UNWRAP_ARGS(ARGS), OPS),        \
334                    Storage, Context.pImpl->CLASS##s)
335 #define DEFINE_GETIMPL_STORE_NO_OPS(CLASS, ARGS)                               \
336   return storeImpl(new (0u, Storage)                                           \
337                        CLASS(Context, Storage, UNWRAP_ARGS(ARGS)),             \
338                    Storage, Context.pImpl->CLASS##s)
339 #define DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(CLASS, OPS)                   \
340   return storeImpl(new (array_lengthof(OPS), Storage)                          \
341                        CLASS(Context, Storage, OPS),                           \
342                    Storage, Context.pImpl->CLASS##s)
343 #define DEFINE_GETIMPL_STORE_N(CLASS, ARGS, OPS, NUM_OPS)                      \
344   return storeImpl(new (NUM_OPS, Storage)                                      \
345                        CLASS(Context, Storage, UNWRAP_ARGS(ARGS), OPS),        \
346                    Storage, Context.pImpl->CLASS##s)
347 
348 DISubrange::DISubrange(LLVMContext &C, StorageType Storage,
349                        ArrayRef<Metadata *> Ops)
350     : DINode(C, DISubrangeKind, Storage, dwarf::DW_TAG_subrange_type, Ops) {}
351 DISubrange *DISubrange::getImpl(LLVMContext &Context, int64_t Count, int64_t Lo,
352                                 StorageType Storage, bool ShouldCreate) {
353   auto *CountNode = ConstantAsMetadata::get(
354       ConstantInt::getSigned(Type::getInt64Ty(Context), Count));
355   auto *LB = ConstantAsMetadata::get(
356       ConstantInt::getSigned(Type::getInt64Ty(Context), Lo));
357   return getImpl(Context, CountNode, LB, nullptr, nullptr, Storage,
358                  ShouldCreate);
359 }
360 
361 DISubrange *DISubrange::getImpl(LLVMContext &Context, Metadata *CountNode,
362                                 int64_t Lo, StorageType Storage,
363                                 bool ShouldCreate) {
364   auto *LB = ConstantAsMetadata::get(
365       ConstantInt::getSigned(Type::getInt64Ty(Context), Lo));
366   return getImpl(Context, CountNode, LB, nullptr, nullptr, Storage,
367                  ShouldCreate);
368 }
369 
370 DISubrange *DISubrange::getImpl(LLVMContext &Context, Metadata *CountNode,
371                                 Metadata *LB, Metadata *UB, Metadata *Stride,
372                                 StorageType Storage, bool ShouldCreate) {
373   DEFINE_GETIMPL_LOOKUP(DISubrange, (CountNode, LB, UB, Stride));
374   Metadata *Ops[] = {CountNode, LB, UB, Stride};
375   DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DISubrange, Ops);
376 }
377 
378 DISubrange::BoundType DISubrange::getCount() const {
379   Metadata *CB = getRawCountNode();
380   if (!CB)
381     return BoundType();
382 
383   assert((isa<ConstantAsMetadata>(CB) || isa<DIVariable>(CB) ||
384           isa<DIExpression>(CB)) &&
385          "Count must be signed constant or DIVariable or DIExpression");
386 
387   if (auto *MD = dyn_cast<ConstantAsMetadata>(CB))
388     return BoundType(cast<ConstantInt>(MD->getValue()));
389 
390   if (auto *MD = dyn_cast<DIVariable>(CB))
391     return BoundType(MD);
392 
393   if (auto *MD = dyn_cast<DIExpression>(CB))
394     return BoundType(MD);
395 
396   return BoundType();
397 }
398 
399 DISubrange::BoundType DISubrange::getLowerBound() const {
400   Metadata *LB = getRawLowerBound();
401   if (!LB)
402     return BoundType();
403 
404   assert((isa<ConstantAsMetadata>(LB) || isa<DIVariable>(LB) ||
405           isa<DIExpression>(LB)) &&
406          "LowerBound must be signed constant or DIVariable or DIExpression");
407 
408   if (auto *MD = dyn_cast<ConstantAsMetadata>(LB))
409     return BoundType(cast<ConstantInt>(MD->getValue()));
410 
411   if (auto *MD = dyn_cast<DIVariable>(LB))
412     return BoundType(MD);
413 
414   if (auto *MD = dyn_cast<DIExpression>(LB))
415     return BoundType(MD);
416 
417   return BoundType();
418 }
419 
420 DISubrange::BoundType DISubrange::getUpperBound() const {
421   Metadata *UB = getRawUpperBound();
422   if (!UB)
423     return BoundType();
424 
425   assert((isa<ConstantAsMetadata>(UB) || isa<DIVariable>(UB) ||
426           isa<DIExpression>(UB)) &&
427          "UpperBound must be signed constant or DIVariable or DIExpression");
428 
429   if (auto *MD = dyn_cast<ConstantAsMetadata>(UB))
430     return BoundType(cast<ConstantInt>(MD->getValue()));
431 
432   if (auto *MD = dyn_cast<DIVariable>(UB))
433     return BoundType(MD);
434 
435   if (auto *MD = dyn_cast<DIExpression>(UB))
436     return BoundType(MD);
437 
438   return BoundType();
439 }
440 
441 DISubrange::BoundType DISubrange::getStride() const {
442   Metadata *ST = getRawStride();
443   if (!ST)
444     return BoundType();
445 
446   assert((isa<ConstantAsMetadata>(ST) || isa<DIVariable>(ST) ||
447           isa<DIExpression>(ST)) &&
448          "Stride must be signed constant or DIVariable or DIExpression");
449 
450   if (auto *MD = dyn_cast<ConstantAsMetadata>(ST))
451     return BoundType(cast<ConstantInt>(MD->getValue()));
452 
453   if (auto *MD = dyn_cast<DIVariable>(ST))
454     return BoundType(MD);
455 
456   if (auto *MD = dyn_cast<DIExpression>(ST))
457     return BoundType(MD);
458 
459   return BoundType();
460 }
461 DIGenericSubrange::DIGenericSubrange(LLVMContext &C, StorageType Storage,
462                                      ArrayRef<Metadata *> Ops)
463     : DINode(C, DIGenericSubrangeKind, Storage, dwarf::DW_TAG_generic_subrange,
464              Ops) {}
465 
466 DIGenericSubrange *DIGenericSubrange::getImpl(LLVMContext &Context,
467                                               Metadata *CountNode, Metadata *LB,
468                                               Metadata *UB, Metadata *Stride,
469                                               StorageType Storage,
470                                               bool ShouldCreate) {
471   DEFINE_GETIMPL_LOOKUP(DIGenericSubrange, (CountNode, LB, UB, Stride));
472   Metadata *Ops[] = {CountNode, LB, UB, Stride};
473   DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DIGenericSubrange, Ops);
474 }
475 
476 DIGenericSubrange::BoundType DIGenericSubrange::getCount() const {
477   Metadata *CB = getRawCountNode();
478   if (!CB)
479     return BoundType();
480 
481   assert((isa<DIVariable>(CB) || isa<DIExpression>(CB)) &&
482          "Count must be signed constant or DIVariable or DIExpression");
483 
484   if (auto *MD = dyn_cast<DIVariable>(CB))
485     return BoundType(MD);
486 
487   if (auto *MD = dyn_cast<DIExpression>(CB))
488     return BoundType(MD);
489 
490   return BoundType();
491 }
492 
493 DIGenericSubrange::BoundType DIGenericSubrange::getLowerBound() const {
494   Metadata *LB = getRawLowerBound();
495   if (!LB)
496     return BoundType();
497 
498   assert((isa<DIVariable>(LB) || isa<DIExpression>(LB)) &&
499          "LowerBound must be signed constant or DIVariable or DIExpression");
500 
501   if (auto *MD = dyn_cast<DIVariable>(LB))
502     return BoundType(MD);
503 
504   if (auto *MD = dyn_cast<DIExpression>(LB))
505     return BoundType(MD);
506 
507   return BoundType();
508 }
509 
510 DIGenericSubrange::BoundType DIGenericSubrange::getUpperBound() const {
511   Metadata *UB = getRawUpperBound();
512   if (!UB)
513     return BoundType();
514 
515   assert((isa<DIVariable>(UB) || isa<DIExpression>(UB)) &&
516          "UpperBound must be signed constant or DIVariable or DIExpression");
517 
518   if (auto *MD = dyn_cast<DIVariable>(UB))
519     return BoundType(MD);
520 
521   if (auto *MD = dyn_cast<DIExpression>(UB))
522     return BoundType(MD);
523 
524   return BoundType();
525 }
526 
527 DIGenericSubrange::BoundType DIGenericSubrange::getStride() const {
528   Metadata *ST = getRawStride();
529   if (!ST)
530     return BoundType();
531 
532   assert((isa<DIVariable>(ST) || isa<DIExpression>(ST)) &&
533          "Stride must be signed constant or DIVariable or DIExpression");
534 
535   if (auto *MD = dyn_cast<DIVariable>(ST))
536     return BoundType(MD);
537 
538   if (auto *MD = dyn_cast<DIExpression>(ST))
539     return BoundType(MD);
540 
541   return BoundType();
542 }
543 
544 DIEnumerator::DIEnumerator(LLVMContext &C, StorageType Storage,
545                            const APInt &Value, bool IsUnsigned,
546                            ArrayRef<Metadata *> Ops)
547     : DINode(C, DIEnumeratorKind, Storage, dwarf::DW_TAG_enumerator, Ops),
548       Value(Value) {
549   SubclassData32 = IsUnsigned;
550 }
551 DIEnumerator *DIEnumerator::getImpl(LLVMContext &Context, const APInt &Value,
552                                     bool IsUnsigned, MDString *Name,
553                                     StorageType Storage, bool ShouldCreate) {
554   assert(isCanonical(Name) && "Expected canonical MDString");
555   DEFINE_GETIMPL_LOOKUP(DIEnumerator, (Value, IsUnsigned, Name));
556   Metadata *Ops[] = {Name};
557   DEFINE_GETIMPL_STORE(DIEnumerator, (Value, IsUnsigned), Ops);
558 }
559 
560 DIBasicType *DIBasicType::getImpl(LLVMContext &Context, unsigned Tag,
561                                   MDString *Name, uint64_t SizeInBits,
562                                   uint32_t AlignInBits, unsigned Encoding,
563                                   DIFlags Flags, StorageType Storage,
564                                   bool ShouldCreate) {
565   assert(isCanonical(Name) && "Expected canonical MDString");
566   DEFINE_GETIMPL_LOOKUP(DIBasicType,
567                         (Tag, Name, SizeInBits, AlignInBits, Encoding, Flags));
568   Metadata *Ops[] = {nullptr, nullptr, Name};
569   DEFINE_GETIMPL_STORE(DIBasicType,
570                        (Tag, SizeInBits, AlignInBits, Encoding, Flags), Ops);
571 }
572 
573 Optional<DIBasicType::Signedness> DIBasicType::getSignedness() const {
574   switch (getEncoding()) {
575   case dwarf::DW_ATE_signed:
576   case dwarf::DW_ATE_signed_char:
577     return Signedness::Signed;
578   case dwarf::DW_ATE_unsigned:
579   case dwarf::DW_ATE_unsigned_char:
580     return Signedness::Unsigned;
581   default:
582     return None;
583   }
584 }
585 
586 DIStringType *DIStringType::getImpl(LLVMContext &Context, unsigned Tag,
587                                     MDString *Name, Metadata *StringLength,
588                                     Metadata *StringLengthExp,
589                                     Metadata *StringLocationExp,
590                                     uint64_t SizeInBits, uint32_t AlignInBits,
591                                     unsigned Encoding, StorageType Storage,
592                                     bool ShouldCreate) {
593   assert(isCanonical(Name) && "Expected canonical MDString");
594   DEFINE_GETIMPL_LOOKUP(DIStringType,
595                         (Tag, Name, StringLength, StringLengthExp,
596                          StringLocationExp, SizeInBits, AlignInBits, Encoding));
597   Metadata *Ops[] = {nullptr,      nullptr,         Name,
598                      StringLength, StringLengthExp, StringLocationExp};
599   DEFINE_GETIMPL_STORE(DIStringType, (Tag, SizeInBits, AlignInBits, Encoding),
600                        Ops);
601 }
602 DIType *DIDerivedType::getClassType() const {
603   assert(getTag() == dwarf::DW_TAG_ptr_to_member_type);
604   return cast_or_null<DIType>(getExtraData());
605 }
606 uint32_t DIDerivedType::getVBPtrOffset() const {
607   assert(getTag() == dwarf::DW_TAG_inheritance);
608   if (auto *CM = cast_or_null<ConstantAsMetadata>(getExtraData()))
609     if (auto *CI = dyn_cast_or_null<ConstantInt>(CM->getValue()))
610       return static_cast<uint32_t>(CI->getZExtValue());
611   return 0;
612 }
613 Constant *DIDerivedType::getStorageOffsetInBits() const {
614   assert(getTag() == dwarf::DW_TAG_member && isBitField());
615   if (auto *C = cast_or_null<ConstantAsMetadata>(getExtraData()))
616     return C->getValue();
617   return nullptr;
618 }
619 
620 Constant *DIDerivedType::getConstant() const {
621   assert(getTag() == dwarf::DW_TAG_member && isStaticMember());
622   if (auto *C = cast_or_null<ConstantAsMetadata>(getExtraData()))
623     return C->getValue();
624   return nullptr;
625 }
626 Constant *DIDerivedType::getDiscriminantValue() const {
627   assert(getTag() == dwarf::DW_TAG_member && !isStaticMember());
628   if (auto *C = cast_or_null<ConstantAsMetadata>(getExtraData()))
629     return C->getValue();
630   return nullptr;
631 }
632 
633 DIDerivedType *DIDerivedType::getImpl(
634     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
635     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
636     uint32_t AlignInBits, uint64_t OffsetInBits,
637     Optional<unsigned> DWARFAddressSpace, DIFlags Flags, Metadata *ExtraData,
638     Metadata *Annotations, StorageType Storage, bool ShouldCreate) {
639   assert(isCanonical(Name) && "Expected canonical MDString");
640   DEFINE_GETIMPL_LOOKUP(DIDerivedType,
641                         (Tag, Name, File, Line, Scope, BaseType, SizeInBits,
642                          AlignInBits, OffsetInBits, DWARFAddressSpace, Flags,
643                          ExtraData, Annotations));
644   Metadata *Ops[] = {File, Scope, Name, BaseType, ExtraData, Annotations};
645   DEFINE_GETIMPL_STORE(DIDerivedType,
646                        (Tag, Line, SizeInBits, AlignInBits, OffsetInBits,
647                         DWARFAddressSpace, Flags),
648                        Ops);
649 }
650 
651 DICompositeType *DICompositeType::getImpl(
652     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
653     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
654     uint32_t AlignInBits, uint64_t OffsetInBits, DIFlags Flags,
655     Metadata *Elements, unsigned RuntimeLang, Metadata *VTableHolder,
656     Metadata *TemplateParams, MDString *Identifier, Metadata *Discriminator,
657     Metadata *DataLocation, Metadata *Associated, Metadata *Allocated,
658     Metadata *Rank, Metadata *Annotations, StorageType Storage,
659     bool ShouldCreate) {
660   assert(isCanonical(Name) && "Expected canonical MDString");
661 
662   // Keep this in sync with buildODRType.
663   DEFINE_GETIMPL_LOOKUP(DICompositeType,
664                         (Tag, Name, File, Line, Scope, BaseType, SizeInBits,
665                          AlignInBits, OffsetInBits, Flags, Elements,
666                          RuntimeLang, VTableHolder, TemplateParams, Identifier,
667                          Discriminator, DataLocation, Associated, Allocated,
668                          Rank, Annotations));
669   Metadata *Ops[] = {File,          Scope,        Name,           BaseType,
670                      Elements,      VTableHolder, TemplateParams, Identifier,
671                      Discriminator, DataLocation, Associated,     Allocated,
672                      Rank,          Annotations};
673   DEFINE_GETIMPL_STORE(
674       DICompositeType,
675       (Tag, Line, RuntimeLang, SizeInBits, AlignInBits, OffsetInBits, Flags),
676       Ops);
677 }
678 
679 DICompositeType *DICompositeType::buildODRType(
680     LLVMContext &Context, MDString &Identifier, unsigned Tag, MDString *Name,
681     Metadata *File, unsigned Line, Metadata *Scope, Metadata *BaseType,
682     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
683     DIFlags Flags, Metadata *Elements, unsigned RuntimeLang,
684     Metadata *VTableHolder, Metadata *TemplateParams, Metadata *Discriminator,
685     Metadata *DataLocation, Metadata *Associated, Metadata *Allocated,
686     Metadata *Rank, Metadata *Annotations) {
687   assert(!Identifier.getString().empty() && "Expected valid identifier");
688   if (!Context.isODRUniquingDebugTypes())
689     return nullptr;
690   auto *&CT = (*Context.pImpl->DITypeMap)[&Identifier];
691   if (!CT)
692     return CT = DICompositeType::getDistinct(
693                Context, Tag, Name, File, Line, Scope, BaseType, SizeInBits,
694                AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang,
695                VTableHolder, TemplateParams, &Identifier, Discriminator,
696                DataLocation, Associated, Allocated, Rank, Annotations);
697 
698   if (CT->getTag() != Tag)
699     return nullptr;
700 
701   // Only mutate CT if it's a forward declaration and the new operands aren't.
702   assert(CT->getRawIdentifier() == &Identifier && "Wrong ODR identifier?");
703   if (!CT->isForwardDecl() || (Flags & DINode::FlagFwdDecl))
704     return CT;
705 
706   // Mutate CT in place.  Keep this in sync with getImpl.
707   CT->mutate(Tag, Line, RuntimeLang, SizeInBits, AlignInBits, OffsetInBits,
708              Flags);
709   Metadata *Ops[] = {File,          Scope,        Name,           BaseType,
710                      Elements,      VTableHolder, TemplateParams, &Identifier,
711                      Discriminator, DataLocation, Associated,     Allocated,
712                      Rank,          Annotations};
713   assert((std::end(Ops) - std::begin(Ops)) == (int)CT->getNumOperands() &&
714          "Mismatched number of operands");
715   for (unsigned I = 0, E = CT->getNumOperands(); I != E; ++I)
716     if (Ops[I] != CT->getOperand(I))
717       CT->setOperand(I, Ops[I]);
718   return CT;
719 }
720 
721 DICompositeType *DICompositeType::getODRType(
722     LLVMContext &Context, MDString &Identifier, unsigned Tag, MDString *Name,
723     Metadata *File, unsigned Line, Metadata *Scope, Metadata *BaseType,
724     uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
725     DIFlags Flags, Metadata *Elements, unsigned RuntimeLang,
726     Metadata *VTableHolder, Metadata *TemplateParams, Metadata *Discriminator,
727     Metadata *DataLocation, Metadata *Associated, Metadata *Allocated,
728     Metadata *Rank, Metadata *Annotations) {
729   assert(!Identifier.getString().empty() && "Expected valid identifier");
730   if (!Context.isODRUniquingDebugTypes())
731     return nullptr;
732   auto *&CT = (*Context.pImpl->DITypeMap)[&Identifier];
733   if (!CT) {
734     CT = DICompositeType::getDistinct(
735         Context, Tag, Name, File, Line, Scope, BaseType, SizeInBits,
736         AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang, VTableHolder,
737         TemplateParams, &Identifier, Discriminator, DataLocation, Associated,
738         Allocated, Rank, Annotations);
739   } else {
740     if (CT->getTag() != Tag)
741       return nullptr;
742   }
743   return CT;
744 }
745 
746 DICompositeType *DICompositeType::getODRTypeIfExists(LLVMContext &Context,
747                                                      MDString &Identifier) {
748   assert(!Identifier.getString().empty() && "Expected valid identifier");
749   if (!Context.isODRUniquingDebugTypes())
750     return nullptr;
751   return Context.pImpl->DITypeMap->lookup(&Identifier);
752 }
753 DISubroutineType::DISubroutineType(LLVMContext &C, StorageType Storage,
754                                    DIFlags Flags, uint8_t CC,
755                                    ArrayRef<Metadata *> Ops)
756     : DIType(C, DISubroutineTypeKind, Storage, dwarf::DW_TAG_subroutine_type, 0,
757              0, 0, 0, Flags, Ops),
758       CC(CC) {}
759 
760 DISubroutineType *DISubroutineType::getImpl(LLVMContext &Context, DIFlags Flags,
761                                             uint8_t CC, Metadata *TypeArray,
762                                             StorageType Storage,
763                                             bool ShouldCreate) {
764   DEFINE_GETIMPL_LOOKUP(DISubroutineType, (Flags, CC, TypeArray));
765   Metadata *Ops[] = {nullptr, nullptr, nullptr, TypeArray};
766   DEFINE_GETIMPL_STORE(DISubroutineType, (Flags, CC), Ops);
767 }
768 
769 DIFile::DIFile(LLVMContext &C, StorageType Storage,
770                Optional<ChecksumInfo<MDString *>> CS, Optional<MDString *> Src,
771                ArrayRef<Metadata *> Ops)
772     : DIScope(C, DIFileKind, Storage, dwarf::DW_TAG_file_type, Ops),
773       Checksum(CS), Source(Src) {}
774 
775 // FIXME: Implement this string-enum correspondence with a .def file and macros,
776 // so that the association is explicit rather than implied.
777 static const char *ChecksumKindName[DIFile::CSK_Last] = {
778     "CSK_MD5",
779     "CSK_SHA1",
780     "CSK_SHA256",
781 };
782 
783 StringRef DIFile::getChecksumKindAsString(ChecksumKind CSKind) {
784   assert(CSKind <= DIFile::CSK_Last && "Invalid checksum kind");
785   // The first space was originally the CSK_None variant, which is now
786   // obsolete, but the space is still reserved in ChecksumKind, so we account
787   // for it here.
788   return ChecksumKindName[CSKind - 1];
789 }
790 
791 Optional<DIFile::ChecksumKind> DIFile::getChecksumKind(StringRef CSKindStr) {
792   return StringSwitch<Optional<DIFile::ChecksumKind>>(CSKindStr)
793       .Case("CSK_MD5", DIFile::CSK_MD5)
794       .Case("CSK_SHA1", DIFile::CSK_SHA1)
795       .Case("CSK_SHA256", DIFile::CSK_SHA256)
796       .Default(None);
797 }
798 
799 DIFile *DIFile::getImpl(LLVMContext &Context, MDString *Filename,
800                         MDString *Directory,
801                         Optional<DIFile::ChecksumInfo<MDString *>> CS,
802                         Optional<MDString *> Source, StorageType Storage,
803                         bool ShouldCreate) {
804   assert(isCanonical(Filename) && "Expected canonical MDString");
805   assert(isCanonical(Directory) && "Expected canonical MDString");
806   assert((!CS || isCanonical(CS->Value)) && "Expected canonical MDString");
807   assert((!Source || isCanonical(*Source)) && "Expected canonical MDString");
808   DEFINE_GETIMPL_LOOKUP(DIFile, (Filename, Directory, CS, Source));
809   Metadata *Ops[] = {Filename, Directory, CS ? CS->Value : nullptr,
810                      Source.value_or(nullptr)};
811   DEFINE_GETIMPL_STORE(DIFile, (CS, Source), Ops);
812 }
813 DICompileUnit::DICompileUnit(LLVMContext &C, StorageType Storage,
814                              unsigned SourceLanguage, bool IsOptimized,
815                              unsigned RuntimeVersion, unsigned EmissionKind,
816                              uint64_t DWOId, bool SplitDebugInlining,
817                              bool DebugInfoForProfiling, unsigned NameTableKind,
818                              bool RangesBaseAddress, ArrayRef<Metadata *> Ops)
819     : DIScope(C, DICompileUnitKind, Storage, dwarf::DW_TAG_compile_unit, Ops),
820       SourceLanguage(SourceLanguage), IsOptimized(IsOptimized),
821       RuntimeVersion(RuntimeVersion), EmissionKind(EmissionKind), DWOId(DWOId),
822       SplitDebugInlining(SplitDebugInlining),
823       DebugInfoForProfiling(DebugInfoForProfiling),
824       NameTableKind(NameTableKind), RangesBaseAddress(RangesBaseAddress) {
825   assert(Storage != Uniqued);
826 }
827 
828 DICompileUnit *DICompileUnit::getImpl(
829     LLVMContext &Context, unsigned SourceLanguage, Metadata *File,
830     MDString *Producer, bool IsOptimized, MDString *Flags,
831     unsigned RuntimeVersion, MDString *SplitDebugFilename,
832     unsigned EmissionKind, Metadata *EnumTypes, Metadata *RetainedTypes,
833     Metadata *GlobalVariables, Metadata *ImportedEntities, Metadata *Macros,
834     uint64_t DWOId, bool SplitDebugInlining, bool DebugInfoForProfiling,
835     unsigned NameTableKind, bool RangesBaseAddress, MDString *SysRoot,
836     MDString *SDK, StorageType Storage, bool ShouldCreate) {
837   assert(Storage != Uniqued && "Cannot unique DICompileUnit");
838   assert(isCanonical(Producer) && "Expected canonical MDString");
839   assert(isCanonical(Flags) && "Expected canonical MDString");
840   assert(isCanonical(SplitDebugFilename) && "Expected canonical MDString");
841 
842   Metadata *Ops[] = {File,
843                      Producer,
844                      Flags,
845                      SplitDebugFilename,
846                      EnumTypes,
847                      RetainedTypes,
848                      GlobalVariables,
849                      ImportedEntities,
850                      Macros,
851                      SysRoot,
852                      SDK};
853   return storeImpl(new (array_lengthof(Ops), Storage) DICompileUnit(
854                        Context, Storage, SourceLanguage, IsOptimized,
855                        RuntimeVersion, EmissionKind, DWOId, SplitDebugInlining,
856                        DebugInfoForProfiling, NameTableKind, RangesBaseAddress,
857                        Ops),
858                    Storage);
859 }
860 
861 Optional<DICompileUnit::DebugEmissionKind>
862 DICompileUnit::getEmissionKind(StringRef Str) {
863   return StringSwitch<Optional<DebugEmissionKind>>(Str)
864       .Case("NoDebug", NoDebug)
865       .Case("FullDebug", FullDebug)
866       .Case("LineTablesOnly", LineTablesOnly)
867       .Case("DebugDirectivesOnly", DebugDirectivesOnly)
868       .Default(None);
869 }
870 
871 Optional<DICompileUnit::DebugNameTableKind>
872 DICompileUnit::getNameTableKind(StringRef Str) {
873   return StringSwitch<Optional<DebugNameTableKind>>(Str)
874       .Case("Default", DebugNameTableKind::Default)
875       .Case("GNU", DebugNameTableKind::GNU)
876       .Case("None", DebugNameTableKind::None)
877       .Default(None);
878 }
879 
880 const char *DICompileUnit::emissionKindString(DebugEmissionKind EK) {
881   switch (EK) {
882   case NoDebug:
883     return "NoDebug";
884   case FullDebug:
885     return "FullDebug";
886   case LineTablesOnly:
887     return "LineTablesOnly";
888   case DebugDirectivesOnly:
889     return "DebugDirectivesOnly";
890   }
891   return nullptr;
892 }
893 
894 const char *DICompileUnit::nameTableKindString(DebugNameTableKind NTK) {
895   switch (NTK) {
896   case DebugNameTableKind::Default:
897     return nullptr;
898   case DebugNameTableKind::GNU:
899     return "GNU";
900   case DebugNameTableKind::None:
901     return "None";
902   }
903   return nullptr;
904 }
905 DISubprogram::DISubprogram(LLVMContext &C, StorageType Storage, unsigned Line,
906                            unsigned ScopeLine, unsigned VirtualIndex,
907                            int ThisAdjustment, DIFlags Flags, DISPFlags SPFlags,
908                            ArrayRef<Metadata *> Ops)
909     : DILocalScope(C, DISubprogramKind, Storage, dwarf::DW_TAG_subprogram, Ops),
910       Line(Line), ScopeLine(ScopeLine), VirtualIndex(VirtualIndex),
911       ThisAdjustment(ThisAdjustment), Flags(Flags), SPFlags(SPFlags) {
912   static_assert(dwarf::DW_VIRTUALITY_max < 4, "Virtuality out of range");
913 }
914 DISubprogram::DISPFlags
915 DISubprogram::toSPFlags(bool IsLocalToUnit, bool IsDefinition, bool IsOptimized,
916                         unsigned Virtuality, bool IsMainSubprogram) {
917   // We're assuming virtuality is the low-order field.
918   static_assert(int(SPFlagVirtual) == int(dwarf::DW_VIRTUALITY_virtual) &&
919                     int(SPFlagPureVirtual) ==
920                         int(dwarf::DW_VIRTUALITY_pure_virtual),
921                 "Virtuality constant mismatch");
922   return static_cast<DISPFlags>(
923       (Virtuality & SPFlagVirtuality) |
924       (IsLocalToUnit ? SPFlagLocalToUnit : SPFlagZero) |
925       (IsDefinition ? SPFlagDefinition : SPFlagZero) |
926       (IsOptimized ? SPFlagOptimized : SPFlagZero) |
927       (IsMainSubprogram ? SPFlagMainSubprogram : SPFlagZero));
928 }
929 
930 DISubprogram *DILocalScope::getSubprogram() const {
931   if (auto *Block = dyn_cast<DILexicalBlockBase>(this))
932     return Block->getScope()->getSubprogram();
933   return const_cast<DISubprogram *>(cast<DISubprogram>(this));
934 }
935 
936 DILocalScope *DILocalScope::getNonLexicalBlockFileScope() const {
937   if (auto *File = dyn_cast<DILexicalBlockFile>(this))
938     return File->getScope()->getNonLexicalBlockFileScope();
939   return const_cast<DILocalScope *>(this);
940 }
941 
942 DISubprogram::DISPFlags DISubprogram::getFlag(StringRef Flag) {
943   return StringSwitch<DISPFlags>(Flag)
944 #define HANDLE_DISP_FLAG(ID, NAME) .Case("DISPFlag" #NAME, SPFlag##NAME)
945 #include "llvm/IR/DebugInfoFlags.def"
946       .Default(SPFlagZero);
947 }
948 
949 StringRef DISubprogram::getFlagString(DISPFlags Flag) {
950   switch (Flag) {
951   // Appease a warning.
952   case SPFlagVirtuality:
953     return "";
954 #define HANDLE_DISP_FLAG(ID, NAME)                                             \
955   case SPFlag##NAME:                                                           \
956     return "DISPFlag" #NAME;
957 #include "llvm/IR/DebugInfoFlags.def"
958   }
959   return "";
960 }
961 
962 DISubprogram::DISPFlags
963 DISubprogram::splitFlags(DISPFlags Flags,
964                          SmallVectorImpl<DISPFlags> &SplitFlags) {
965   // Multi-bit fields can require special handling. In our case, however, the
966   // only multi-bit field is virtuality, and all its values happen to be
967   // single-bit values, so the right behavior just falls out.
968 #define HANDLE_DISP_FLAG(ID, NAME)                                             \
969   if (DISPFlags Bit = Flags & SPFlag##NAME) {                                  \
970     SplitFlags.push_back(Bit);                                                 \
971     Flags &= ~Bit;                                                             \
972   }
973 #include "llvm/IR/DebugInfoFlags.def"
974   return Flags;
975 }
976 
977 DISubprogram *DISubprogram::getImpl(
978     LLVMContext &Context, Metadata *Scope, MDString *Name,
979     MDString *LinkageName, Metadata *File, unsigned Line, Metadata *Type,
980     unsigned ScopeLine, Metadata *ContainingType, unsigned VirtualIndex,
981     int ThisAdjustment, DIFlags Flags, DISPFlags SPFlags, Metadata *Unit,
982     Metadata *TemplateParams, Metadata *Declaration, Metadata *RetainedNodes,
983     Metadata *ThrownTypes, Metadata *Annotations, MDString *TargetFuncName,
984     StorageType Storage, bool ShouldCreate) {
985   assert(isCanonical(Name) && "Expected canonical MDString");
986   assert(isCanonical(LinkageName) && "Expected canonical MDString");
987   assert(isCanonical(TargetFuncName) && "Expected canonical MDString");
988   DEFINE_GETIMPL_LOOKUP(DISubprogram,
989                         (Scope, Name, LinkageName, File, Line, Type, ScopeLine,
990                          ContainingType, VirtualIndex, ThisAdjustment, Flags,
991                          SPFlags, Unit, TemplateParams, Declaration,
992                          RetainedNodes, ThrownTypes, Annotations,
993                          TargetFuncName));
994   SmallVector<Metadata *, 13> Ops = {
995       File,           Scope,          Name,        LinkageName,
996       Type,           Unit,           Declaration, RetainedNodes,
997       ContainingType, TemplateParams, ThrownTypes, Annotations,
998       TargetFuncName};
999   if (!TargetFuncName) {
1000     Ops.pop_back();
1001     if (!Annotations) {
1002       Ops.pop_back();
1003       if (!ThrownTypes) {
1004         Ops.pop_back();
1005         if (!TemplateParams) {
1006           Ops.pop_back();
1007           if (!ContainingType)
1008             Ops.pop_back();
1009         }
1010       }
1011     }
1012   }
1013   DEFINE_GETIMPL_STORE_N(
1014       DISubprogram,
1015       (Line, ScopeLine, VirtualIndex, ThisAdjustment, Flags, SPFlags), Ops,
1016       Ops.size());
1017 }
1018 
1019 bool DISubprogram::describes(const Function *F) const {
1020   assert(F && "Invalid function");
1021   return F->getSubprogram() == this;
1022 }
1023 DILexicalBlockBase::DILexicalBlockBase(LLVMContext &C, unsigned ID,
1024                                        StorageType Storage,
1025                                        ArrayRef<Metadata *> Ops)
1026     : DILocalScope(C, ID, Storage, dwarf::DW_TAG_lexical_block, Ops) {}
1027 
1028 DILexicalBlock *DILexicalBlock::getImpl(LLVMContext &Context, Metadata *Scope,
1029                                         Metadata *File, unsigned Line,
1030                                         unsigned Column, StorageType Storage,
1031                                         bool ShouldCreate) {
1032   // Fixup column.
1033   adjustColumn(Column);
1034 
1035   assert(Scope && "Expected scope");
1036   DEFINE_GETIMPL_LOOKUP(DILexicalBlock, (Scope, File, Line, Column));
1037   Metadata *Ops[] = {File, Scope};
1038   DEFINE_GETIMPL_STORE(DILexicalBlock, (Line, Column), Ops);
1039 }
1040 
1041 DILexicalBlockFile *DILexicalBlockFile::getImpl(LLVMContext &Context,
1042                                                 Metadata *Scope, Metadata *File,
1043                                                 unsigned Discriminator,
1044                                                 StorageType Storage,
1045                                                 bool ShouldCreate) {
1046   assert(Scope && "Expected scope");
1047   DEFINE_GETIMPL_LOOKUP(DILexicalBlockFile, (Scope, File, Discriminator));
1048   Metadata *Ops[] = {File, Scope};
1049   DEFINE_GETIMPL_STORE(DILexicalBlockFile, (Discriminator), Ops);
1050 }
1051 
1052 DINamespace::DINamespace(LLVMContext &Context, StorageType Storage,
1053                          bool ExportSymbols, ArrayRef<Metadata *> Ops)
1054     : DIScope(Context, DINamespaceKind, Storage, dwarf::DW_TAG_namespace, Ops),
1055       ExportSymbols(ExportSymbols) {}
1056 DINamespace *DINamespace::getImpl(LLVMContext &Context, Metadata *Scope,
1057                                   MDString *Name, bool ExportSymbols,
1058                                   StorageType Storage, bool ShouldCreate) {
1059   assert(isCanonical(Name) && "Expected canonical MDString");
1060   DEFINE_GETIMPL_LOOKUP(DINamespace, (Scope, Name, ExportSymbols));
1061   // The nullptr is for DIScope's File operand. This should be refactored.
1062   Metadata *Ops[] = {nullptr, Scope, Name};
1063   DEFINE_GETIMPL_STORE(DINamespace, (ExportSymbols), Ops);
1064 }
1065 
1066 DICommonBlock::DICommonBlock(LLVMContext &Context, StorageType Storage,
1067                              unsigned LineNo, ArrayRef<Metadata *> Ops)
1068     : DIScope(Context, DICommonBlockKind, Storage, dwarf::DW_TAG_common_block,
1069               Ops),
1070       LineNo(LineNo) {}
1071 DICommonBlock *DICommonBlock::getImpl(LLVMContext &Context, Metadata *Scope,
1072                                       Metadata *Decl, MDString *Name,
1073                                       Metadata *File, unsigned LineNo,
1074                                       StorageType Storage, bool ShouldCreate) {
1075   assert(isCanonical(Name) && "Expected canonical MDString");
1076   DEFINE_GETIMPL_LOOKUP(DICommonBlock, (Scope, Decl, Name, File, LineNo));
1077   // The nullptr is for DIScope's File operand. This should be refactored.
1078   Metadata *Ops[] = {Scope, Decl, Name, File};
1079   DEFINE_GETIMPL_STORE(DICommonBlock, (LineNo), Ops);
1080 }
1081 
1082 DIModule::DIModule(LLVMContext &Context, StorageType Storage, unsigned LineNo,
1083                    bool IsDecl, ArrayRef<Metadata *> Ops)
1084     : DIScope(Context, DIModuleKind, Storage, dwarf::DW_TAG_module, Ops),
1085       LineNo(LineNo), IsDecl(IsDecl) {}
1086 DIModule *DIModule::getImpl(LLVMContext &Context, Metadata *File,
1087                             Metadata *Scope, MDString *Name,
1088                             MDString *ConfigurationMacros,
1089                             MDString *IncludePath, MDString *APINotesFile,
1090                             unsigned LineNo, bool IsDecl, StorageType Storage,
1091                             bool ShouldCreate) {
1092   assert(isCanonical(Name) && "Expected canonical MDString");
1093   DEFINE_GETIMPL_LOOKUP(DIModule, (File, Scope, Name, ConfigurationMacros,
1094                                    IncludePath, APINotesFile, LineNo, IsDecl));
1095   Metadata *Ops[] = {File,        Scope,       Name, ConfigurationMacros,
1096                      IncludePath, APINotesFile};
1097   DEFINE_GETIMPL_STORE(DIModule, (LineNo, IsDecl), Ops);
1098 }
1099 DITemplateTypeParameter::DITemplateTypeParameter(LLVMContext &Context,
1100                                                  StorageType Storage,
1101                                                  bool IsDefault,
1102                                                  ArrayRef<Metadata *> Ops)
1103     : DITemplateParameter(Context, DITemplateTypeParameterKind, Storage,
1104                           dwarf::DW_TAG_template_type_parameter, IsDefault,
1105                           Ops) {}
1106 
1107 DITemplateTypeParameter *
1108 DITemplateTypeParameter::getImpl(LLVMContext &Context, MDString *Name,
1109                                  Metadata *Type, bool isDefault,
1110                                  StorageType Storage, bool ShouldCreate) {
1111   assert(isCanonical(Name) && "Expected canonical MDString");
1112   DEFINE_GETIMPL_LOOKUP(DITemplateTypeParameter, (Name, Type, isDefault));
1113   Metadata *Ops[] = {Name, Type};
1114   DEFINE_GETIMPL_STORE(DITemplateTypeParameter, (isDefault), Ops);
1115 }
1116 
1117 DITemplateValueParameter *DITemplateValueParameter::getImpl(
1118     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *Type,
1119     bool isDefault, Metadata *Value, StorageType Storage, bool ShouldCreate) {
1120   assert(isCanonical(Name) && "Expected canonical MDString");
1121   DEFINE_GETIMPL_LOOKUP(DITemplateValueParameter,
1122                         (Tag, Name, Type, isDefault, Value));
1123   Metadata *Ops[] = {Name, Type, Value};
1124   DEFINE_GETIMPL_STORE(DITemplateValueParameter, (Tag, isDefault), Ops);
1125 }
1126 
1127 DIGlobalVariable *
1128 DIGlobalVariable::getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
1129                           MDString *LinkageName, Metadata *File, unsigned Line,
1130                           Metadata *Type, bool IsLocalToUnit, bool IsDefinition,
1131                           Metadata *StaticDataMemberDeclaration,
1132                           Metadata *TemplateParams, uint32_t AlignInBits,
1133                           Metadata *Annotations, StorageType Storage,
1134                           bool ShouldCreate) {
1135   assert(isCanonical(Name) && "Expected canonical MDString");
1136   assert(isCanonical(LinkageName) && "Expected canonical MDString");
1137   DEFINE_GETIMPL_LOOKUP(
1138       DIGlobalVariable,
1139       (Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit, IsDefinition,
1140        StaticDataMemberDeclaration, TemplateParams, AlignInBits, Annotations));
1141   Metadata *Ops[] = {Scope,
1142                      Name,
1143                      File,
1144                      Type,
1145                      Name,
1146                      LinkageName,
1147                      StaticDataMemberDeclaration,
1148                      TemplateParams,
1149                      Annotations};
1150   DEFINE_GETIMPL_STORE(DIGlobalVariable,
1151                        (Line, IsLocalToUnit, IsDefinition, AlignInBits), Ops);
1152 }
1153 
1154 DILocalVariable *
1155 DILocalVariable::getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
1156                          Metadata *File, unsigned Line, Metadata *Type,
1157                          unsigned Arg, DIFlags Flags, uint32_t AlignInBits,
1158                          Metadata *Annotations, StorageType Storage,
1159                          bool ShouldCreate) {
1160   // 64K ought to be enough for any frontend.
1161   assert(Arg <= UINT16_MAX && "Expected argument number to fit in 16-bits");
1162 
1163   assert(Scope && "Expected scope");
1164   assert(isCanonical(Name) && "Expected canonical MDString");
1165   DEFINE_GETIMPL_LOOKUP(DILocalVariable, (Scope, Name, File, Line, Type, Arg,
1166                                           Flags, AlignInBits, Annotations));
1167   Metadata *Ops[] = {Scope, Name, File, Type, Annotations};
1168   DEFINE_GETIMPL_STORE(DILocalVariable, (Line, Arg, Flags, AlignInBits), Ops);
1169 }
1170 
1171 DIVariable::DIVariable(LLVMContext &C, unsigned ID, StorageType Storage,
1172                        signed Line, ArrayRef<Metadata *> Ops,
1173                        uint32_t AlignInBits)
1174     : DINode(C, ID, Storage, dwarf::DW_TAG_variable, Ops), Line(Line),
1175       AlignInBits(AlignInBits) {}
1176 Optional<uint64_t> DIVariable::getSizeInBits() const {
1177   // This is used by the Verifier so be mindful of broken types.
1178   const Metadata *RawType = getRawType();
1179   while (RawType) {
1180     // Try to get the size directly.
1181     if (auto *T = dyn_cast<DIType>(RawType))
1182       if (uint64_t Size = T->getSizeInBits())
1183         return Size;
1184 
1185     if (auto *DT = dyn_cast<DIDerivedType>(RawType)) {
1186       // Look at the base type.
1187       RawType = DT->getRawBaseType();
1188       continue;
1189     }
1190 
1191     // Missing type or size.
1192     break;
1193   }
1194 
1195   // Fail gracefully.
1196   return None;
1197 }
1198 
1199 DILabel::DILabel(LLVMContext &C, StorageType Storage, unsigned Line,
1200                  ArrayRef<Metadata *> Ops)
1201     : DINode(C, DILabelKind, Storage, dwarf::DW_TAG_label, Ops), Line(Line) {}
1202 DILabel *DILabel::getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
1203                           Metadata *File, unsigned Line, StorageType Storage,
1204                           bool ShouldCreate) {
1205   assert(Scope && "Expected scope");
1206   assert(isCanonical(Name) && "Expected canonical MDString");
1207   DEFINE_GETIMPL_LOOKUP(DILabel, (Scope, Name, File, Line));
1208   Metadata *Ops[] = {Scope, Name, File};
1209   DEFINE_GETIMPL_STORE(DILabel, (Line), Ops);
1210 }
1211 
1212 DIExpression *DIExpression::getImpl(LLVMContext &Context,
1213                                     ArrayRef<uint64_t> Elements,
1214                                     StorageType Storage, bool ShouldCreate) {
1215   DEFINE_GETIMPL_LOOKUP(DIExpression, (Elements));
1216   DEFINE_GETIMPL_STORE_NO_OPS(DIExpression, (Elements));
1217 }
1218 bool DIExpression::isEntryValue() const {
1219   return getNumElements() > 0 && getElement(0) == dwarf::DW_OP_LLVM_entry_value;
1220 }
1221 bool DIExpression::startsWithDeref() const {
1222   return getNumElements() > 0 && getElement(0) == dwarf::DW_OP_deref;
1223 }
1224 
1225 unsigned DIExpression::ExprOperand::getSize() const {
1226   uint64_t Op = getOp();
1227 
1228   if (Op >= dwarf::DW_OP_breg0 && Op <= dwarf::DW_OP_breg31)
1229     return 2;
1230 
1231   switch (Op) {
1232   case dwarf::DW_OP_LLVM_convert:
1233   case dwarf::DW_OP_LLVM_fragment:
1234   case dwarf::DW_OP_bregx:
1235     return 3;
1236   case dwarf::DW_OP_constu:
1237   case dwarf::DW_OP_consts:
1238   case dwarf::DW_OP_deref_size:
1239   case dwarf::DW_OP_plus_uconst:
1240   case dwarf::DW_OP_LLVM_tag_offset:
1241   case dwarf::DW_OP_LLVM_entry_value:
1242   case dwarf::DW_OP_LLVM_arg:
1243   case dwarf::DW_OP_regx:
1244     return 2;
1245   default:
1246     return 1;
1247   }
1248 }
1249 
1250 bool DIExpression::isValid() const {
1251   for (auto I = expr_op_begin(), E = expr_op_end(); I != E; ++I) {
1252     // Check that there's space for the operand.
1253     if (I->get() + I->getSize() > E->get())
1254       return false;
1255 
1256     uint64_t Op = I->getOp();
1257     if ((Op >= dwarf::DW_OP_reg0 && Op <= dwarf::DW_OP_reg31) ||
1258         (Op >= dwarf::DW_OP_breg0 && Op <= dwarf::DW_OP_breg31))
1259       return true;
1260 
1261     // Check that the operand is valid.
1262     switch (Op) {
1263     default:
1264       return false;
1265     case dwarf::DW_OP_LLVM_fragment:
1266       // A fragment operator must appear at the end.
1267       return I->get() + I->getSize() == E->get();
1268     case dwarf::DW_OP_stack_value: {
1269       // Must be the last one or followed by a DW_OP_LLVM_fragment.
1270       if (I->get() + I->getSize() == E->get())
1271         break;
1272       auto J = I;
1273       if ((++J)->getOp() != dwarf::DW_OP_LLVM_fragment)
1274         return false;
1275       break;
1276     }
1277     case dwarf::DW_OP_swap: {
1278       // Must be more than one implicit element on the stack.
1279 
1280       // FIXME: A better way to implement this would be to add a local variable
1281       // that keeps track of the stack depth and introduce something like a
1282       // DW_LLVM_OP_implicit_location as a placeholder for the location this
1283       // DIExpression is attached to, or else pass the number of implicit stack
1284       // elements into isValid.
1285       if (getNumElements() == 1)
1286         return false;
1287       break;
1288     }
1289     case dwarf::DW_OP_LLVM_entry_value: {
1290       // An entry value operator must appear at the beginning and the number of
1291       // operations it cover can currently only be 1, because we support only
1292       // entry values of a simple register location. One reason for this is that
1293       // we currently can't calculate the size of the resulting DWARF block for
1294       // other expressions.
1295       return I->get() == expr_op_begin()->get() && I->getArg(0) == 1;
1296     }
1297     case dwarf::DW_OP_LLVM_implicit_pointer:
1298     case dwarf::DW_OP_LLVM_convert:
1299     case dwarf::DW_OP_LLVM_arg:
1300     case dwarf::DW_OP_LLVM_tag_offset:
1301     case dwarf::DW_OP_constu:
1302     case dwarf::DW_OP_plus_uconst:
1303     case dwarf::DW_OP_plus:
1304     case dwarf::DW_OP_minus:
1305     case dwarf::DW_OP_mul:
1306     case dwarf::DW_OP_div:
1307     case dwarf::DW_OP_mod:
1308     case dwarf::DW_OP_or:
1309     case dwarf::DW_OP_and:
1310     case dwarf::DW_OP_xor:
1311     case dwarf::DW_OP_shl:
1312     case dwarf::DW_OP_shr:
1313     case dwarf::DW_OP_shra:
1314     case dwarf::DW_OP_deref:
1315     case dwarf::DW_OP_deref_size:
1316     case dwarf::DW_OP_xderef:
1317     case dwarf::DW_OP_lit0:
1318     case dwarf::DW_OP_not:
1319     case dwarf::DW_OP_dup:
1320     case dwarf::DW_OP_regx:
1321     case dwarf::DW_OP_bregx:
1322     case dwarf::DW_OP_push_object_address:
1323     case dwarf::DW_OP_over:
1324     case dwarf::DW_OP_consts:
1325       break;
1326     }
1327   }
1328   return true;
1329 }
1330 
1331 bool DIExpression::isImplicit() const {
1332   if (!isValid())
1333     return false;
1334 
1335   if (getNumElements() == 0)
1336     return false;
1337 
1338   for (const auto &It : expr_ops()) {
1339     switch (It.getOp()) {
1340     default:
1341       break;
1342     case dwarf::DW_OP_stack_value:
1343     case dwarf::DW_OP_LLVM_tag_offset:
1344       return true;
1345     }
1346   }
1347 
1348   return false;
1349 }
1350 
1351 bool DIExpression::isComplex() const {
1352   if (!isValid())
1353     return false;
1354 
1355   if (getNumElements() == 0)
1356     return false;
1357 
1358   // If there are any elements other than fragment or tag_offset, then some
1359   // kind of complex computation occurs.
1360   for (const auto &It : expr_ops()) {
1361     switch (It.getOp()) {
1362     case dwarf::DW_OP_LLVM_tag_offset:
1363     case dwarf::DW_OP_LLVM_fragment:
1364       continue;
1365     default:
1366       return true;
1367     }
1368   }
1369 
1370   return false;
1371 }
1372 
1373 Optional<DIExpression::FragmentInfo>
1374 DIExpression::getFragmentInfo(expr_op_iterator Start, expr_op_iterator End) {
1375   for (auto I = Start; I != End; ++I)
1376     if (I->getOp() == dwarf::DW_OP_LLVM_fragment) {
1377       DIExpression::FragmentInfo Info = {I->getArg(1), I->getArg(0)};
1378       return Info;
1379     }
1380   return None;
1381 }
1382 
1383 void DIExpression::appendOffset(SmallVectorImpl<uint64_t> &Ops,
1384                                 int64_t Offset) {
1385   if (Offset > 0) {
1386     Ops.push_back(dwarf::DW_OP_plus_uconst);
1387     Ops.push_back(Offset);
1388   } else if (Offset < 0) {
1389     Ops.push_back(dwarf::DW_OP_constu);
1390     Ops.push_back(-Offset);
1391     Ops.push_back(dwarf::DW_OP_minus);
1392   }
1393 }
1394 
1395 bool DIExpression::extractIfOffset(int64_t &Offset) const {
1396   if (getNumElements() == 0) {
1397     Offset = 0;
1398     return true;
1399   }
1400 
1401   if (getNumElements() == 2 && Elements[0] == dwarf::DW_OP_plus_uconst) {
1402     Offset = Elements[1];
1403     return true;
1404   }
1405 
1406   if (getNumElements() == 3 && Elements[0] == dwarf::DW_OP_constu) {
1407     if (Elements[2] == dwarf::DW_OP_plus) {
1408       Offset = Elements[1];
1409       return true;
1410     }
1411     if (Elements[2] == dwarf::DW_OP_minus) {
1412       Offset = -Elements[1];
1413       return true;
1414     }
1415   }
1416 
1417   return false;
1418 }
1419 
1420 bool DIExpression::hasAllLocationOps(unsigned N) const {
1421   SmallDenseSet<uint64_t, 4> SeenOps;
1422   for (auto ExprOp : expr_ops())
1423     if (ExprOp.getOp() == dwarf::DW_OP_LLVM_arg)
1424       SeenOps.insert(ExprOp.getArg(0));
1425   for (uint64_t Idx = 0; Idx < N; ++Idx)
1426     if (!is_contained(SeenOps, Idx))
1427       return false;
1428   return true;
1429 }
1430 
1431 const DIExpression *DIExpression::extractAddressClass(const DIExpression *Expr,
1432                                                       unsigned &AddrClass) {
1433   // FIXME: This seems fragile. Nothing that verifies that these elements
1434   // actually map to ops and not operands.
1435   const unsigned PatternSize = 4;
1436   if (Expr->Elements.size() >= PatternSize &&
1437       Expr->Elements[PatternSize - 4] == dwarf::DW_OP_constu &&
1438       Expr->Elements[PatternSize - 2] == dwarf::DW_OP_swap &&
1439       Expr->Elements[PatternSize - 1] == dwarf::DW_OP_xderef) {
1440     AddrClass = Expr->Elements[PatternSize - 3];
1441 
1442     if (Expr->Elements.size() == PatternSize)
1443       return nullptr;
1444     return DIExpression::get(Expr->getContext(),
1445                              makeArrayRef(&*Expr->Elements.begin(),
1446                                           Expr->Elements.size() - PatternSize));
1447   }
1448   return Expr;
1449 }
1450 
1451 DIExpression *DIExpression::prepend(const DIExpression *Expr, uint8_t Flags,
1452                                     int64_t Offset) {
1453   SmallVector<uint64_t, 8> Ops;
1454   if (Flags & DIExpression::DerefBefore)
1455     Ops.push_back(dwarf::DW_OP_deref);
1456 
1457   appendOffset(Ops, Offset);
1458   if (Flags & DIExpression::DerefAfter)
1459     Ops.push_back(dwarf::DW_OP_deref);
1460 
1461   bool StackValue = Flags & DIExpression::StackValue;
1462   bool EntryValue = Flags & DIExpression::EntryValue;
1463 
1464   return prependOpcodes(Expr, Ops, StackValue, EntryValue);
1465 }
1466 
1467 DIExpression *DIExpression::appendOpsToArg(const DIExpression *Expr,
1468                                            ArrayRef<uint64_t> Ops,
1469                                            unsigned ArgNo, bool StackValue) {
1470   assert(Expr && "Can't add ops to this expression");
1471 
1472   // Handle non-variadic intrinsics by prepending the opcodes.
1473   if (!any_of(Expr->expr_ops(),
1474               [](auto Op) { return Op.getOp() == dwarf::DW_OP_LLVM_arg; })) {
1475     assert(ArgNo == 0 &&
1476            "Location Index must be 0 for a non-variadic expression.");
1477     SmallVector<uint64_t, 8> NewOps(Ops.begin(), Ops.end());
1478     return DIExpression::prependOpcodes(Expr, NewOps, StackValue);
1479   }
1480 
1481   SmallVector<uint64_t, 8> NewOps;
1482   for (auto Op : Expr->expr_ops()) {
1483     Op.appendToVector(NewOps);
1484     if (Op.getOp() == dwarf::DW_OP_LLVM_arg && Op.getArg(0) == ArgNo)
1485       NewOps.insert(NewOps.end(), Ops.begin(), Ops.end());
1486   }
1487 
1488   return DIExpression::get(Expr->getContext(), NewOps);
1489 }
1490 
1491 DIExpression *DIExpression::replaceArg(const DIExpression *Expr,
1492                                        uint64_t OldArg, uint64_t NewArg) {
1493   assert(Expr && "Can't replace args in this expression");
1494 
1495   SmallVector<uint64_t, 8> NewOps;
1496 
1497   for (auto Op : Expr->expr_ops()) {
1498     if (Op.getOp() != dwarf::DW_OP_LLVM_arg || Op.getArg(0) < OldArg) {
1499       Op.appendToVector(NewOps);
1500       continue;
1501     }
1502     NewOps.push_back(dwarf::DW_OP_LLVM_arg);
1503     uint64_t Arg = Op.getArg(0) == OldArg ? NewArg : Op.getArg(0);
1504     // OldArg has been deleted from the Op list, so decrement all indices
1505     // greater than it.
1506     if (Arg > OldArg)
1507       --Arg;
1508     NewOps.push_back(Arg);
1509   }
1510   return DIExpression::get(Expr->getContext(), NewOps);
1511 }
1512 
1513 DIExpression *DIExpression::prependOpcodes(const DIExpression *Expr,
1514                                            SmallVectorImpl<uint64_t> &Ops,
1515                                            bool StackValue, bool EntryValue) {
1516   assert(Expr && "Can't prepend ops to this expression");
1517 
1518   if (EntryValue) {
1519     Ops.push_back(dwarf::DW_OP_LLVM_entry_value);
1520     // Use a block size of 1 for the target register operand.  The
1521     // DWARF backend currently cannot emit entry values with a block
1522     // size > 1.
1523     Ops.push_back(1);
1524   }
1525 
1526   // If there are no ops to prepend, do not even add the DW_OP_stack_value.
1527   if (Ops.empty())
1528     StackValue = false;
1529   for (auto Op : Expr->expr_ops()) {
1530     // A DW_OP_stack_value comes at the end, but before a DW_OP_LLVM_fragment.
1531     if (StackValue) {
1532       if (Op.getOp() == dwarf::DW_OP_stack_value)
1533         StackValue = false;
1534       else if (Op.getOp() == dwarf::DW_OP_LLVM_fragment) {
1535         Ops.push_back(dwarf::DW_OP_stack_value);
1536         StackValue = false;
1537       }
1538     }
1539     Op.appendToVector(Ops);
1540   }
1541   if (StackValue)
1542     Ops.push_back(dwarf::DW_OP_stack_value);
1543   return DIExpression::get(Expr->getContext(), Ops);
1544 }
1545 
1546 DIExpression *DIExpression::append(const DIExpression *Expr,
1547                                    ArrayRef<uint64_t> Ops) {
1548   assert(Expr && !Ops.empty() && "Can't append ops to this expression");
1549 
1550   // Copy Expr's current op list.
1551   SmallVector<uint64_t, 16> NewOps;
1552   for (auto Op : Expr->expr_ops()) {
1553     // Append new opcodes before DW_OP_{stack_value, LLVM_fragment}.
1554     if (Op.getOp() == dwarf::DW_OP_stack_value ||
1555         Op.getOp() == dwarf::DW_OP_LLVM_fragment) {
1556       NewOps.append(Ops.begin(), Ops.end());
1557 
1558       // Ensure that the new opcodes are only appended once.
1559       Ops = None;
1560     }
1561     Op.appendToVector(NewOps);
1562   }
1563 
1564   NewOps.append(Ops.begin(), Ops.end());
1565   auto *result = DIExpression::get(Expr->getContext(), NewOps);
1566   assert(result->isValid() && "concatenated expression is not valid");
1567   return result;
1568 }
1569 
1570 DIExpression *DIExpression::appendToStack(const DIExpression *Expr,
1571                                           ArrayRef<uint64_t> Ops) {
1572   assert(Expr && !Ops.empty() && "Can't append ops to this expression");
1573   assert(none_of(Ops,
1574                  [](uint64_t Op) {
1575                    return Op == dwarf::DW_OP_stack_value ||
1576                           Op == dwarf::DW_OP_LLVM_fragment;
1577                  }) &&
1578          "Can't append this op");
1579 
1580   // Append a DW_OP_deref after Expr's current op list if it's non-empty and
1581   // has no DW_OP_stack_value.
1582   //
1583   // Match .* DW_OP_stack_value (DW_OP_LLVM_fragment A B)?.
1584   Optional<FragmentInfo> FI = Expr->getFragmentInfo();
1585   unsigned DropUntilStackValue = FI ? 3 : 0;
1586   ArrayRef<uint64_t> ExprOpsBeforeFragment =
1587       Expr->getElements().drop_back(DropUntilStackValue);
1588   bool NeedsDeref = (Expr->getNumElements() > DropUntilStackValue) &&
1589                     (ExprOpsBeforeFragment.back() != dwarf::DW_OP_stack_value);
1590   bool NeedsStackValue = NeedsDeref || ExprOpsBeforeFragment.empty();
1591 
1592   // Append a DW_OP_deref after Expr's current op list if needed, then append
1593   // the new ops, and finally ensure that a single DW_OP_stack_value is present.
1594   SmallVector<uint64_t, 16> NewOps;
1595   if (NeedsDeref)
1596     NewOps.push_back(dwarf::DW_OP_deref);
1597   NewOps.append(Ops.begin(), Ops.end());
1598   if (NeedsStackValue)
1599     NewOps.push_back(dwarf::DW_OP_stack_value);
1600   return DIExpression::append(Expr, NewOps);
1601 }
1602 
1603 Optional<DIExpression *> DIExpression::createFragmentExpression(
1604     const DIExpression *Expr, unsigned OffsetInBits, unsigned SizeInBits) {
1605   SmallVector<uint64_t, 8> Ops;
1606   // Copy over the expression, but leave off any trailing DW_OP_LLVM_fragment.
1607   if (Expr) {
1608     for (auto Op : Expr->expr_ops()) {
1609       switch (Op.getOp()) {
1610       default:
1611         break;
1612       case dwarf::DW_OP_shr:
1613       case dwarf::DW_OP_shra:
1614       case dwarf::DW_OP_shl:
1615       case dwarf::DW_OP_plus:
1616       case dwarf::DW_OP_plus_uconst:
1617       case dwarf::DW_OP_minus:
1618         // We can't safely split arithmetic or shift operations into multiple
1619         // fragments because we can't express carry-over between fragments.
1620         //
1621         // FIXME: We *could* preserve the lowest fragment of a constant offset
1622         // operation if the offset fits into SizeInBits.
1623         return None;
1624       case dwarf::DW_OP_LLVM_fragment: {
1625         // Make the new offset point into the existing fragment.
1626         uint64_t FragmentOffsetInBits = Op.getArg(0);
1627         uint64_t FragmentSizeInBits = Op.getArg(1);
1628         (void)FragmentSizeInBits;
1629         assert((OffsetInBits + SizeInBits <= FragmentSizeInBits) &&
1630                "new fragment outside of original fragment");
1631         OffsetInBits += FragmentOffsetInBits;
1632         continue;
1633       }
1634       }
1635       Op.appendToVector(Ops);
1636     }
1637   }
1638   assert(Expr && "Unknown DIExpression");
1639   Ops.push_back(dwarf::DW_OP_LLVM_fragment);
1640   Ops.push_back(OffsetInBits);
1641   Ops.push_back(SizeInBits);
1642   return DIExpression::get(Expr->getContext(), Ops);
1643 }
1644 
1645 std::pair<DIExpression *, const ConstantInt *>
1646 DIExpression::constantFold(const ConstantInt *CI) {
1647   // Copy the APInt so we can modify it.
1648   APInt NewInt = CI->getValue();
1649   SmallVector<uint64_t, 8> Ops;
1650 
1651   // Fold operators only at the beginning of the expression.
1652   bool First = true;
1653   bool Changed = false;
1654   for (auto Op : expr_ops()) {
1655     switch (Op.getOp()) {
1656     default:
1657       // We fold only the leading part of the expression; if we get to a part
1658       // that we're going to copy unchanged, and haven't done any folding,
1659       // then the entire expression is unchanged and we can return early.
1660       if (!Changed)
1661         return {this, CI};
1662       First = false;
1663       break;
1664     case dwarf::DW_OP_LLVM_convert:
1665       if (!First)
1666         break;
1667       Changed = true;
1668       if (Op.getArg(1) == dwarf::DW_ATE_signed)
1669         NewInt = NewInt.sextOrTrunc(Op.getArg(0));
1670       else {
1671         assert(Op.getArg(1) == dwarf::DW_ATE_unsigned && "Unexpected operand");
1672         NewInt = NewInt.zextOrTrunc(Op.getArg(0));
1673       }
1674       continue;
1675     }
1676     Op.appendToVector(Ops);
1677   }
1678   if (!Changed)
1679     return {this, CI};
1680   return {DIExpression::get(getContext(), Ops),
1681           ConstantInt::get(getContext(), NewInt)};
1682 }
1683 
1684 uint64_t DIExpression::getNumLocationOperands() const {
1685   uint64_t Result = 0;
1686   for (auto ExprOp : expr_ops())
1687     if (ExprOp.getOp() == dwarf::DW_OP_LLVM_arg)
1688       Result = std::max(Result, ExprOp.getArg(0) + 1);
1689   assert(hasAllLocationOps(Result) &&
1690          "Expression is missing one or more location operands.");
1691   return Result;
1692 }
1693 
1694 llvm::Optional<DIExpression::SignedOrUnsignedConstant>
1695 DIExpression::isConstant() const {
1696 
1697   // Recognize signed and unsigned constants.
1698   // An signed constants can be represented as DW_OP_consts C DW_OP_stack_value
1699   // (DW_OP_LLVM_fragment of Len).
1700   // An unsigned constant can be represented as
1701   // DW_OP_constu C DW_OP_stack_value (DW_OP_LLVM_fragment of Len).
1702 
1703   if ((getNumElements() != 2 && getNumElements() != 3 &&
1704        getNumElements() != 6) ||
1705       (getElement(0) != dwarf::DW_OP_consts &&
1706        getElement(0) != dwarf::DW_OP_constu))
1707     return None;
1708 
1709   if (getNumElements() == 2 && getElement(0) == dwarf::DW_OP_consts)
1710     return SignedOrUnsignedConstant::SignedConstant;
1711 
1712   if ((getNumElements() == 3 && getElement(2) != dwarf::DW_OP_stack_value) ||
1713       (getNumElements() == 6 && (getElement(2) != dwarf::DW_OP_stack_value ||
1714                                  getElement(3) != dwarf::DW_OP_LLVM_fragment)))
1715     return None;
1716   return getElement(0) == dwarf::DW_OP_constu
1717              ? SignedOrUnsignedConstant::UnsignedConstant
1718              : SignedOrUnsignedConstant::SignedConstant;
1719 }
1720 
1721 DIExpression::ExtOps DIExpression::getExtOps(unsigned FromSize, unsigned ToSize,
1722                                              bool Signed) {
1723   dwarf::TypeKind TK = Signed ? dwarf::DW_ATE_signed : dwarf::DW_ATE_unsigned;
1724   DIExpression::ExtOps Ops{{dwarf::DW_OP_LLVM_convert, FromSize, TK,
1725                             dwarf::DW_OP_LLVM_convert, ToSize, TK}};
1726   return Ops;
1727 }
1728 
1729 DIExpression *DIExpression::appendExt(const DIExpression *Expr,
1730                                       unsigned FromSize, unsigned ToSize,
1731                                       bool Signed) {
1732   return appendToStack(Expr, getExtOps(FromSize, ToSize, Signed));
1733 }
1734 
1735 DIGlobalVariableExpression *
1736 DIGlobalVariableExpression::getImpl(LLVMContext &Context, Metadata *Variable,
1737                                     Metadata *Expression, StorageType Storage,
1738                                     bool ShouldCreate) {
1739   DEFINE_GETIMPL_LOOKUP(DIGlobalVariableExpression, (Variable, Expression));
1740   Metadata *Ops[] = {Variable, Expression};
1741   DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DIGlobalVariableExpression, Ops);
1742 }
1743 DIObjCProperty::DIObjCProperty(LLVMContext &C, StorageType Storage,
1744                                unsigned Line, unsigned Attributes,
1745                                ArrayRef<Metadata *> Ops)
1746     : DINode(C, DIObjCPropertyKind, Storage, dwarf::DW_TAG_APPLE_property, Ops),
1747       Line(Line), Attributes(Attributes) {}
1748 
1749 DIObjCProperty *DIObjCProperty::getImpl(
1750     LLVMContext &Context, MDString *Name, Metadata *File, unsigned Line,
1751     MDString *GetterName, MDString *SetterName, unsigned Attributes,
1752     Metadata *Type, StorageType Storage, bool ShouldCreate) {
1753   assert(isCanonical(Name) && "Expected canonical MDString");
1754   assert(isCanonical(GetterName) && "Expected canonical MDString");
1755   assert(isCanonical(SetterName) && "Expected canonical MDString");
1756   DEFINE_GETIMPL_LOOKUP(DIObjCProperty, (Name, File, Line, GetterName,
1757                                          SetterName, Attributes, Type));
1758   Metadata *Ops[] = {Name, File, GetterName, SetterName, Type};
1759   DEFINE_GETIMPL_STORE(DIObjCProperty, (Line, Attributes), Ops);
1760 }
1761 
1762 DIImportedEntity *DIImportedEntity::getImpl(LLVMContext &Context, unsigned Tag,
1763                                             Metadata *Scope, Metadata *Entity,
1764                                             Metadata *File, unsigned Line,
1765                                             MDString *Name, Metadata *Elements,
1766                                             StorageType Storage,
1767                                             bool ShouldCreate) {
1768   assert(isCanonical(Name) && "Expected canonical MDString");
1769   DEFINE_GETIMPL_LOOKUP(DIImportedEntity,
1770                         (Tag, Scope, Entity, File, Line, Name, Elements));
1771   Metadata *Ops[] = {Scope, Entity, Name, File, Elements};
1772   DEFINE_GETIMPL_STORE(DIImportedEntity, (Tag, Line), Ops);
1773 }
1774 
1775 DIMacro *DIMacro::getImpl(LLVMContext &Context, unsigned MIType, unsigned Line,
1776                           MDString *Name, MDString *Value, StorageType Storage,
1777                           bool ShouldCreate) {
1778   assert(isCanonical(Name) && "Expected canonical MDString");
1779   DEFINE_GETIMPL_LOOKUP(DIMacro, (MIType, Line, Name, Value));
1780   Metadata *Ops[] = {Name, Value};
1781   DEFINE_GETIMPL_STORE(DIMacro, (MIType, Line), Ops);
1782 }
1783 
1784 DIMacroFile *DIMacroFile::getImpl(LLVMContext &Context, unsigned MIType,
1785                                   unsigned Line, Metadata *File,
1786                                   Metadata *Elements, StorageType Storage,
1787                                   bool ShouldCreate) {
1788   DEFINE_GETIMPL_LOOKUP(DIMacroFile, (MIType, Line, File, Elements));
1789   Metadata *Ops[] = {File, Elements};
1790   DEFINE_GETIMPL_STORE(DIMacroFile, (MIType, Line), Ops);
1791 }
1792 
1793 DIArgList *DIArgList::getImpl(LLVMContext &Context,
1794                               ArrayRef<ValueAsMetadata *> Args,
1795                               StorageType Storage, bool ShouldCreate) {
1796   DEFINE_GETIMPL_LOOKUP(DIArgList, (Args));
1797   DEFINE_GETIMPL_STORE_NO_OPS(DIArgList, (Args));
1798 }
1799 
1800 void DIArgList::handleChangedOperand(void *Ref, Metadata *New) {
1801   ValueAsMetadata **OldVMPtr = static_cast<ValueAsMetadata **>(Ref);
1802   assert((!New || isa<ValueAsMetadata>(New)) &&
1803          "DIArgList must be passed a ValueAsMetadata");
1804   untrack();
1805   bool Uniq = isUniqued();
1806   if (Uniq) {
1807     // We need to update the uniqueness once the Args are updated since they
1808     // form the key to the DIArgLists store.
1809     eraseFromStore();
1810   }
1811   ValueAsMetadata *NewVM = cast_or_null<ValueAsMetadata>(New);
1812   for (ValueAsMetadata *&VM : Args) {
1813     if (&VM == OldVMPtr) {
1814       if (NewVM)
1815         VM = NewVM;
1816       else
1817         VM = ValueAsMetadata::get(UndefValue::get(VM->getValue()->getType()));
1818     }
1819   }
1820   if (Uniq) {
1821     if (uniquify() != this)
1822       storeDistinctInContext();
1823   }
1824   track();
1825 }
1826 void DIArgList::track() {
1827   for (ValueAsMetadata *&VAM : Args)
1828     if (VAM)
1829       MetadataTracking::track(&VAM, *VAM, *this);
1830 }
1831 void DIArgList::untrack() {
1832   for (ValueAsMetadata *&VAM : Args)
1833     if (VAM)
1834       MetadataTracking::untrack(&VAM, *VAM);
1835 }
1836 void DIArgList::dropAllReferences() {
1837   untrack();
1838   Args.clear();
1839   MDNode::dropAllReferences();
1840 }
1841